Heretofore, for example, in the diagnosis or the like of infectious diseases, sample analysis tools for detecting antigens of pathogens such as bacteria and viruses utilizing an immunoreaction are in widespread use. In such sample analysis tools, immunochromatography (hereinafter also may be referred to as an “immunoassay method”) is used widely because it allows quantitative analysis, semi-quantitative analysis, qualitative analysis, or the like to be performed easily and rapidly. In recent years, an immunoassay method in which an enzyme is used as a label (hereinafter, such a method may also be referred to as an “enzyme immunoassay method”) has been developed (see Patent Document 1, for example).
As shown in FIG. 6, a conventional sample analysis tool 60 generally is configured so that a development member 61 is contained in a plastic case 66. FIG. 6A is a plan view of the sample analysis tool. FIG. 6B is a sectional view of the sample analysis tool, viewed along arrows III-III in FIG. 6A. In FIGS. 6A and 6B, common components and portions are given the same reference numerals. In the development member 61, a developing solution supply portion 62, a sample supply portion 63, and a detection portion 64 are provided in this order from upstream to downstream along the flow of a developing solution (from the right to the left in FIGS. 6A and 6B). In the detection portion 64, an antibody is immobilized (hereinafter, the antibody may also be referred to as the “immobilized antibody”). In the plastic case 66, a developing solution supply port 67, a sample supply port 68, and a window 69 are formed. The developing solution supply port 67 is provided so that the lower end thereof is in contact with the developing solution supply portion 62. The sample supply port 68 is provided above the sample supply portion 63. The window 69 is provided above the detection portion 64.